Known alkenylphenol compounds include alkenylphenols obtained from phenols and allyl chloride as disclosed in Organic Rca-Lion II, p. 27 (1949) and diallylbisphenols obtained from bisphenols as disclosed in U.S. Pat. No. 2,910,455. Also known are compositions comprising the alkenylphenols and a maleimide compound (see JP-B-55-39242, the term "JP-B" as used herein means an "examined Japanese patent publication"), compositions comprising the alkenylphenols, a maleimide compound, and an epoxy resin (see JP-A-53-134099, the term "JP-A" as used herein means an "unexamined published Japanese patent application"), and compositions comprising the alkenylphenols, a maleimide compound, and a hydrazide.
When these conventional alkenylphenols are used for crosslinking reaction, a high temperature and a long time are required for completion of the crosslinking reaction, and the resulting crosslinked product has insufficient heat resistance. It has therefore been demanded to develop a compound free from these disadvantages.